Clinocottus acuticeps (Gilbert, 1896)

Diagnostic Morphological Features

Clinocottus acuticeps is identified by a flattened, three-branched papilla near the anus, and cirri present on the eyeballs, head, lateral line, and at the tip of each dorsal fin spine.

Lateral Line Structure

The lateral line sits high close to the head, curves downward along the middle of the flanks, and straightens as it approaches the caudal peduncle. Each of the first 15 lateral line pores has a slender cirrus.

Anal Fin Characteristics

The penultimate ray of the anal fin is the longest.

Paired and Caudal Fin Structure

Pectoral fins extend to or just past the origin of the anal fin, and the caudal fin is rounded.

Fin Ray Counts

Dorsal fins have between 7 and 9 spines and 14 to 16 soft rays, while the anal fin has 13 to 16 soft rays.

Maximum Size

This species reaches a maximum published total length of 6.4 cm (2.5 in).

Body Coloration Baseline

Their coloration varies based on habitat; individuals may be almost uniformly bright green, but the typical upper body color ranges from green to light brown, marked with dark wedge-shaped saddles that are widest at their lower edge.

Lateral Line Markings

Individuals sometimes have a dark horizontal stripe along the lateral line that may be interrupted by pale spots.

Underside Coloration

The underside is creamy to white.

Ocular Radiating Markings

Three dark radiating lines extend from the eye: the first runs to the snout, the second down to the rear of the mouth, and the third backward to the base of the preopercular spine.

Dorsal Fin Markings

There is a dark blotch on the spiny dorsal fin between the first and third spines.

General Fin Coloration

All fins except the plain pelvic fins are typically dusky with indistinct mottling or barring.

Species Distribution Range

Clinocottus acuticeps occurs in the Eastern Pacific Ocean along the North American Pacific coast, ranging from the Bering Sea to the Big Sur River in central California.

General Habitat

It is common in rocky intertidal and subtidal areas, as well as on sand substrates, among eelgrass Zostera and macroalgae.

Habitat Movement Adaptations

If tidal pool water conditions become unsuitable, this species may leave the pool, and it sometimes enters fresh water.

Preferred Substrate

It prefers sand, gravel, and rock substrates that host mussels of the genus Mytilus.